Contaminated red onions behind salmonella outbreak in 34 states, FDA identifies one company as likely source
An outbreak of salmonella infections in 34 states across the US, which has made close to 400 people sick, has now been linked to red onions by the US Food and Drug Administration (FDA). On July 10, the Centers for Disease Control and Prevention (CDC) PulseNet -- a national laboratory network that connects foodborne illness cases to detect outbreaks -- identified an outbreak of 13 Salmonella Newport infections in three states. Since being identified, the outbreak has rapidly grown. A total of 396 people infected with the outbreak strain of Salmonella Newport have been reported as of July 29. Of 236 ill people with information available, 59 hospitalizations have been reported. No deaths have been reported so far.
The FDA, along with the CDC and state and local partners, has been investigating the multistate outbreak of Salmonella Newport infections. The Public Health Agency of Canada is also investigating an outbreak of Salmonella Newport illnesses that have a genetic fingerprint closely related to the US outbreak.
Epidemiologic and traceback information showed that red onions are the likely source of this outbreak, says the FDA. The agency has identified Thomson International, Inc. of Bakersfield, California, as a likely source of the potentially contaminated red onions. The investigation is ongoing to determine the source of contamination and if additional products are linked to illness. “Investigators in the US and Canada have been collaborating to identify the source of this outbreak. On July 30, 2020, Canadian health officials announced that they had determined red onions from the US to be the potential source of the Canadian outbreak. The Canadian investigation has also prompted a recall warning by the Canadian Food Inspection Agency. Building on this information, and on epidemiologic information on the US outbreak from CDC, the FDA’s traceback investigation was able to identify Thomson International, Inc. as a likely source of contaminated red onions in the US,” says the FDA.
Thomson International has notified the FDA that it will be recalling all varieties of onions that could have come in contact with potentially contaminated red onions, due to the risk of cross-contamination. “This recall would include red, white, yellow, and sweet onions from Thomson International, Inc. Recall information will be made public as soon as it is available from Thomson International, Inc,” says the agency.
Salmonella are a group of bacteria that can cause gastrointestinal illness and fever called salmonellosis. Most people infected with Salmonella develop diarrhea, fever, and stomach cramps six hours to six days after being exposed to the bacteria. The illness usually lasts four to seven days, and most people recover without treatment. In some people, the illness may be so severe that the patient needs to be hospitalized. Salmonella infection may spread from the intestines to the bloodstream and then to other places in the body. Children younger than five years, adults 65 years and older, and people with weakened immune systems are more likely to have a severe illness, say experts. The CDC estimates that approximately 450 persons in the US die each year from acute salmonellosis.
According to the CDC, illnesses started on dates ranging from June 19 to July 12 in the US. People who fell sick range in age from less than one to 102 years, with a median age of 39. The agency explains that illnesses might not yet be reported due to the time it takes between when a person becomes ill and when the illness is reported. This takes an average of two to four weeks. “Whole-genome sequencing analysis of 48 isolates from ill people did not predict any antibiotic resistance. Standard antibiotic susceptibility testing by CDC’s National Antimicrobial Resistance Monitoring System (NARMS) laboratory is underway. Whole-genome sequencing analysis shows that an outbreak of Salmonella Newport infections in Canada is related genetically to this outbreak in the US. This means that people in both of these outbreaks likely share a common source of infection,” the findings reveal.
Both the CDC and the FDA have urged consumers, restaurants, retailers, suppliers, and distributors to not use, eat, sell, serve, or ship red, white, yellow, or sweet onions from Thomson International, or products containing such onions. “If you can’t tell where your onions are from, don’t eat them. Throw them away. If you made any foods with onions and you don’t know where they are from, do not eat them. Throw them away, even if no one got sick. Wash and sanitize any surfaces that may have come in contact with onions or their packaging, such as countertops, refrigerator drawers, knives, and cutting boards,” experts recommend.
“If there has been potential cross-contamination or mixing of onions from other sources with onions from Thomson International, suppliers and distributors should discard all co-mingled and potentially cross-contaminated products,” says the FDA.
Another multistate outbreak of Salmonella linked to backyard poultry
A separate outbreak of Salmonella infections in 48 states has been linked to contact with poultry in backyard flocks, such as chicks and ducklings. The number of illnesses reported this year exceeds the number reported at the same time of the year in previous outbreaks linked to backyard flocks, according to the CDC.
After the first illness was reported in January, the CDC has identified 15 multistate outbreaks. Since the last update on June 24, 473 more ill people and four additional Salmonella serotypes (Braenderup, Muenchen, Thompson, and Typhimurium) were added to the investigation. As of July 28, a total of 938 people infected with one of the outbreak strains of Salmonella have been reported from 48 states. Ill people range in age from less than one year to 94 years, with a median age of 32. An estimated 28% of ill people are children younger than five years of age. The CDC says that of 461 people with information available, 151 people (33%) have been hospitalized, and one death has been reported in Oklahoma.
Of 409 people interviewed, 303 (74%) reported contact with chicks and ducklings before becoming ill. Testing of backyard poultry and their environments (such as backyard coops) in Kentucky and Oregon found three of the outbreak strains. Ill people reported buying poultry from many sources, including agricultural stores, websites, and hatcheries. No single store chain or hatchery accounts for all of the illnesses, said the CDC. The agency suggest frequently washing hands, not kissing backyard poultry or snuggling with them and then touching the face or mouth, and not allowing backyard poultry inside the house, especially in areas where food or drink is prepared, served, or stored.
“You can get sick with a Salmonella infection from touching backyard poultry or their environment. Backyard poultry can carry Salmonella bacteria even if they look healthy and clean and show no signs of illness. Stay healthy around your backyard flock by washing your hands, keeping your birds outside your house, and supervising young children around your flock,” the CDC recommends.